Hello Dan,
I got a call from my daughter that there was a plating question.
She got the heads up from Lee Ann.
The $68 price you were quoted is a very good price.
The option would be to have the workpieces "Banadized".
The reason I bring that up is two fold.
1) This is a thermal application and Banadize is the very best thermal barrier I know of that can be applied in this fashion.
(a workpiece that has been Banadized can have a small corner ground through to the parent material. You can then apply heat up to and beyond the melting point of that material. The material will "pour" out leaving a "shell" of Banadize.
2) The natural "slickness" that comes from the Banadizing process.
There is only "one" place that does that process, and that is the place that developed it.
The US Navy is one of their biggest customers.
Another is Magnuson, I have seen stacks of their blower housings there.
The Banadize process is only for aluminum.
Remember, if you call out a thickness, say .003 for instance......
That will be .003 "in" & .003 "out".
That is to say the process will penetrate the parent material .003 "and" build up .003.
Very good medicine.
http://www.lovattprocesses.com/index1.htm
Take care,
MM